[The_bluester (Paul)]

You probably could do that but this was rooted in my workflow where I tend to build a good LRGB image and then layer the NB over that, rather than build a really nice bicolour or tricolour narrowband image and then lay in RGB stars. I try to make an RGB or LRGB image that I would be happy with as a stand alone before adding the NB.

Andy's comment elsewhere in this thread suggests he processed this one in the same way I do, building the RGB image and then layering in the NB.